Development and validation of a vision and night driving questionnaire.

School of Optometry and Vision Science, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.

2

School of Public Health, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.

Abstract

PURPOSE:

Night-time driving difficulties are a common concern of older drivers and those with eye disease. This study aimed to develop and validate a questionnaire for assessing vision-related night driving difficulties in older drivers.

METHODS:

Items from existing vision-related quality of life questionnaires and driving studies were used to develop a questionnaire that was completed by 283 participants who reported visual difficulties for night driving (65% female, 50 to >80 years). The questionnaire included items relating to demographic and night driving characteristics (seven items), general vision ratings (eight items), vision-related night driving difficulties (11 items), and a single open question about specific night driving difficulties. The vision-related night driving difficulty items were analysed separately using Rasch analysis to form the vision and night driving questionnaire (VND-Q). Rasch analysis assessed validity and psychometric properties of the scale. Generalised linear regression models examined associations between VND-Q scores and age, gender, amount of night driving, self-rated vision, and eye conditions. Test-retest repeatability was assessed using intra-class correlation analysis and Bland-Altman methods of agreement for a subset of 30 participants.

CONCLUSIONS:

The nine-item VND-Q is a unidimensional and reliable questionnaire allowing quantification of the level of visual difficulties that older drivers report at night. The development of this questionnaire is an important step in providing a reliable and validated instrument for use to guide appropriate investigations, referrals, or interventions in clinical and research settings.